Related papers: Electronic Structures in C60-Polymers (review)
Band structures of C60-polymers are studied changing conjugation conditions and the electron number. We use a Su-Schrieffer-Heeger type semiempirical model. In the neutral C60-polymer, electronic structures change among direct-gap insulator…
Variations in the band structures of C60-polymers are studied, when pi-conjugation conditions are changed. We look at band structures in order to discuss a metal-insulator transition, using a semi-empirical model with the…
We study the antiferromagnetic phase of the C60-polymer doped with one electron per one C60 by using a tight-binding model with long-range Coulomb interactions. The model is solved by the unrestricted Hartree-Fock approximation, and a phase…
Variations in the band structures of the two-dimensional C60-polymers are studied, when pi-conjugation conditions are changed. We investigate the rectangular and triangular polymers, in order to discuss metal-insulator transitions, using a…
We derive a model for the highest occupied molecular orbital band of a C60 crystal which includes on-site electron-electron interactions. The form of the interactions are based on the icosahedral symmetry of the C60 molecule together with a…
Charge-transfer (CT) exciton effects are investigated for the optical absorption spectra of crosslinked C60 systems by using the intermediate exciton theory. We consider the C60-dimers, and the two (and three) molecule systems of the…
Although C$_{60}$ is a molecular crystal with a bandgap E$_g$ of ~2.5 eV, we show that E$_g$ is strongly affected by injected charge. In sharp contrast to the Coulomb blockade typical of quantum dots, E$_g$ is {\it reduced} by the Coulomb…
Using density functional methods we calculated structural and electronic properties of bulk chloroform and bromoform intercalated C60, C60 2CHX3 (X=Cl,Br). Both compounds are narrow band insulator materials with a gap between valence and…
Charge-transfer (CT) exciton effects are investigated for the optical absorption spectra of crosslinked C60 systems by using the intermediate exciton theory. We consider the C60-dimers, and the two (and three) molecule systems of the…
The recent experimental fabrication of monolayer and few-layer C60 polymers paves the way for synthesizing two-dimensional cluster-assembled materials. Compared to atoms with the SO(3) symmetry, clusters as superatoms (e.g., C60) have an…
We observe, with angle-resolved photoemission, a dramatic change in the electronic structure of two C60 monolayers, deposited respectively on Ag (111) and (100) substrates, and similarly doped with potassium to half-filling of the C60…
We review the recent theoretical treatment of fullerenes as pi-conjugated systems. Polaronic properties due to the Jahn-Teller type effects are mainly discussed. (1) A Su-Schrieffer-Heeger type electron-phonon model is applied to…
Recently fabricated InSe monolayers exhibit remarkable characteristics that indicate the potential of this material to host a number of many-body phenomena. Here, we consistently describe collective electronic effects in hole-doped InSe…
We study the interplay between charge doping and intermolecular distance in the polymerization of C60 fullerene chains by means of density functional theory (DFT)-based first principle calculations. The potential energy surface analysis…
We extend the Su-Schrieffer-Heeger model of polyacetylene to C_{60} and C_{70} molecules, and solve numerically. The calculations of the undoped systems agree well with the known results. When the system (C_{60} or C_{70}) is doped with one…
The multiplet structure induced by the Coulomb interactions in C$_{60}^{n-}$ ($n = 1 - 12$) is analyzed. The partially ocuppied LUMO gives rise to a set of levels which fill a relatively wide band ( $\approx 2-3$ eV ). A large ($\sim 1$ eV)…
The proposal of using the field-effect for doping organic crystals has raised enormous interest. To assess the feasibility of such an approach, we investigate the effect of a strong electric field on the electronic structure of C60…
Metallic K3C60 shows pronounced structure and a sharp Fermi edge in integrated photoemission spectra (PES) while the insulating K4C60 and K6C60 phases display only a broad structureless peak. We find that both types of spectra can be…
Using density functional theory calculations we investigate the electronic structure of graphene doped by deposition of foreign atoms. We demonstrate that, as the charge transfer to the graphene layer increases, the band structure of the…
The polymer phases of AC60 form distinct crystal structures characterized by the mutual orientations of the (C60-)n chains. We show that the direct electric quadrupole interaction between chains always favors the orthorhombic structure Pmnn…